Aerial ladder

ABSTRACT

This invention discloses an aerial ladder or lift apparatus including a fixed vertical column to be mounted on a transport vehicle of the usual type, the upper end of the upright column being provided with a ladder assembly, which ladder assembly is connected to a mechanism provided in the column to raise and lower the outer end thereof, there being provided a personnel platform at the outer end of said ladder to be raised and lowered therewith. The ladder assembly is of the telescopic type and arranged to move from a horizontal position by means of the interconnection of an intermediate portion of the ladder with the column mechanism, a portion of which is provided with hydraulic instrumentalities adapted to be extended and retracted. The combination of this arrangement with linkage intermediate a vertically fixed member in the column from which a link is connected to a point on the ladder will effect the raising and lowering described. The ladder unit is, by reason of the construction set forth, susceptible of being mounted on virtually any kind of transport vehicle and as an example adjacent the driver station with the column extending up through the roof of the body structure whether the same be a van or not, or at least adjacent such body structure, and still rotatable and swingable as stated, to provide for raising personnel directly on the platform or providing access to the platform by the ladder means provided, there being controls in or at the personnel platform and at the driver station for regulating movement of the respective parts as required to position the same where necessary.

United States Patent [72] lnventor ThomasR.Ha1l Portland,0reg. [21] Appl.No. 716,049 [22] Filed Mar.26, 1968 [45] Patented Mar. 30, 1971 [73] Assignee Altec Manufacturing Company, Inc.

[54] AERIAL LADDER 3 Claims, 6 Drawing Figs.

[52] U.S.Cl 182/67, 182/2 [51] lnt.Cl. E06c5/06 [50] FieldofSearch l82/2,66, 65,67

[56] References Cited UNITED STATES PATENTS 383,828 5/1888 Preston 182/66 2,724,620 11/1955 Johnson.... 182/2 2,936,848 5/1960 Hall 182/2 3,154,199 10/1964 Balogh 182/2 3,197,036 7/1965 Mason 182/65 3,243,123 5/1966 lngraham 182/2 Primary Examiner-Reinaldo P. Machado Attorney-Robb & Robb ABSTRACT: This invention discloses an aerial ladder or lift apparatus including a fixed vertical column to be mounted on a transport vehicle of the usual type, the upper end of the upright column being provided with a ladder assembly, which ladder assembly is connected to a mechanism provided in the column to raise and lower the outer end thereof, there being provided a personnel platform at the outer end of said ladder to be raised and lowered therewith. The ladder assembly is of the telescopic type and arranged to move from a horizontal position by means of the interconnection of an intermediate portion of the ladder with the column mechanism, a portion of which is provided with hydraulic instrumentalities adapted to be extended and retracted. The combination of this arrangement with linkage intermediate a vertically fixed member in the column from which a-link is connected to a point on the ladder will effect the raising and lowering described. The

ladder unit is, by reason of the construction set forth, susceptible of being mounted on virtually any kind of transport vehicle and as an example adjacent the driver station with the column extending up through the roof of the body structure whether the same be a van or not, or at least adjacent such body structure, and still rotatable and swingable as stated, to provide for raising personnel directly on the platform or providing access to the platform by the ladder means provided, there being controls in or at the personnel platform and at the driver station for regulating movement of the respective parts as required to position the same where necessary.

Patented March so, 1971 3,512,467

3 Sheets-Sheet 1 INVENTOR. 7'. FR. HA 1.1..

3 Sheets-Sheet 2 //w F// r V Fig.2

INVENTOR. 7 F? HA L 1..

Patented March 30,1971 3,512,467

3 Sheets-Sheet 5 UP OUT ON 0-0 OI-0 DOWN \N DOWN IN QF'F L LEFT ram-w TOP BOTTOM Rea.

INVENTCR. Fig.6 TRHA' AERIAL LADDER A primary object of this invention is to provide improved aerial lift apparatus, in which a single unit may be mounted on a transport vehicle extending upwardly therefrom and having connection with a ladder assembly in a typical manner, suitaole linkage being provided to effect the raising and lowering of the outer end of the ladder assembly, this being equipped with a personnel platform or basket so that irrespective of the type of body structure, whether the same be a van for example, a unit of this kind may be mounted thereon so as to be availed of in a manner similar to known aerial lift apparatus.

A particular object of the invention is to so arrange the operating mechanism that the same may be readily attached to a transport of any given construction, and be self-contained in the sense that it will not require much of the additional structure heretofore required in usual aerial lift apparatus and yet additionally provide for access directly to the personnel platform by a ladder in the form of ladder sections by which access to the basket may be had irrespective of the attitude of the ladder assembly.

An even more particular object of the invention is to provide mechanism which may be substantially completely enclosed in the single unit provided, whereby increased facility of installation is possible and yet manipulation of the ladder and/or the platform at the end thereof is as flexible, if nbt more so, than known aerial lift apparatus presently in use.

Another object of the invention which is disclosed hereby,

resides in the unique construction of the column itself so that all the various functions required by the general construction and layout of the mechanism are carried out readily with leveling mechanism provided for the personnel platform, rapid and controlled extension and retraction of the ladder sections is accomplished, and positive swinging with nicety of rotative action is available, hydraulic means being compactly arranged within the column for effecting the raising and lowering of the ladder assembly in use.

Other and further objects of the invention will be understood from a consideration of the specification appended hereto and disclosed in the drawings wherein:

FIG. 1 is a partly sectional view in side elevation of the apparatus of this invention incorporated in a transport vehicle, illustrating the method of mounting the same and structural connections provided.

FIG. 2 is a fragmentary view illustrating in enlarged detail the actual construction of the column and certain portions of the operating mechanism incorporated therein.

FIG. 3 is a fragmentary sectional view of the ladder assembly itself to illustrate in some detail the telescopic arrangement thereof.

'FiG. 4 is a diagrammatic view largely, to illustrate the extending and retracting mechanism and connections thereof for the ladder sections.

FlG. 5 is a diagrammatic disclosure of the wiring diagram availed of.

FIG. 6 is a schematic view illustrating the hydraulic system for raising and lowering of the assembly.

Referring now to FIG. 1, a transport vehicle designated 1 is shown, and comprises front and rear wheels 2 and 3 respectively, with a cab mounted on the chassis of the vehicle which is not illustrated in detail, a bed designated 5 extending rearwardly from the cab 4 and having the upstanding sides 6 thereon which are duplicated at opposite sides of the bed as will be readily understood.

The driver station is of course within the cab 4 so that the driver may manipulate the transport vehicle in accordance with usual operation thereof.

it should be noted as suggested by the dotted lines outlining a van section designated 7, the vehicle hereof may have a van body thereon or be provided with an open rear flat bed as illustrated in solid lines herein, this being one of the objectives of the invention to provide mechanism which may be equally easily mounted on such a vehicle, whether the same be of the open type or of the van type as will be pointed out more specifically hereinafter.

Mounted on the bed 5 and adjacent the driver station in the cab 4, is a base unit designated 8 more particularly shown in FIG. 2 in enlarged detail, said unit 3 being fixed to the chassis bed of the vehicle, and having a vertical column 9 extending from said base, and suitably fastened thereto in a rigid manner to accommodate the strain and stresses developed by ladder structure as will be set forth.

Referring momentarily to the disclosure of FIG. 2, as indicated the base 8 and column 9 are suitably connected together, column 9 including a cylindrical shell l0 of suitably heavy construction and being cylindrical as indicated, within which is mounteda rotatable element ll, likewise cylindrical and carried in a bearing 12 at the lower end of the member 10, a suitable thrust bearing 13 being provided at the upper end of the member lll'to provide for rotation of the rotatable element ll therewithin.

The member 11 is equipped with flange 14 which locates the member ll within part lih the rotatable element ll having at its upper end an offstanding arm l5 welded or otherwise secured to the said element ll, with a suitable bushing l6 pressed within the upper end of the element 11.

At the lower end, element ll is fastened to a large spur gear 17 so that rotation of the spur gear 17 will in turn impart rotative motion to the said member and thereby to the arm 15.

The rotation of the member ll as effected by the gear 17 is in turn the result of rotation of a small spur gear 18 mounted on a drive shaft 19, which in turn is driven by a worm gear reduction unit 20 not shown in detail, but of known construction, the same being of the self-locking type and driven by an electric motor for example.

Mounted within the rotatable element ll, is an extensible and retractable member 2l which is cylindrical likewise and forms the outer part of an hydraulic piston and cylinder arrangement in which the inner member 22 thereof is likewise cylindrical.

A suitable bearing 23 is provided having small openings extending therethrough, and at the lower end the part 2l is closed by an end part 24 which provides for a connection 25 from an hydraulic pressure source carried by the tube 26.

The lower end of the inner member 22 is additionally pro vided with a ring 27 which is fastened both to the element ll and part 22 by welding or the like.

From the foregoing, it will be seen that introduction of hydraulic fluid into the member 22 and pressurizing of the same will cause the fluid to flow upwardly therewithin over the open upper end of the member, down through the openings in the bearing 23 and against the seals 30. Since the end of the member 21 is closed as by a cover member 3l, the member 2l will be raised to carry with it the pivot 32 fixed thereto.

Referring now again to FIG. 1, having described the vertical column 9 in some detail, it will be seen that suitably connected to the pivot 32, is the ladder assembly generally designated 33 at 34. This point 34 is of course a pivotal connection and intermediate the ends of the ladder section 35 which is the main or first ladder section.

Suitably spaced from the pivotal connection at 34, is another pivotal connection 36 which is engaged by a link 37, the link 37 in turn being connected at its lower end to a pivot 38 which pivot 38 is mounted in the opening 15a in the arm 15 previously referred to.

it will be seen from this arrangement that extending or pressurizing the piston and cylinder arrangement, including the parts 21 and 22, will cause the member 2l to be extended out of the rotatable element ll so to speak, and by reason of the fixed connection provided by the link'37 cause a raising action of the ladder assembly 33.

The ladder assembly 33 will now be described in detail, and as illustrated in FlGS. l and 3 is comprised of the first or main section 35, the second section 39 and a third section ill, the section 35 being a relatively heavily constructed and formed member which includes a pair of oppositely disposed rails 35a and 35b which are identical in formation but of the opposite hand each having an integral stiffening flange 35c and 35d respectively along the upper edges thereof.

The lower edges 35e and 35f respectively provide further stiffening and support for rungs 4] extending between the rails 35a and 35b. The rungs are suitably fastened to the flanges 35s and 35f and additionally there are provided suitable angles 42 extending along the rails above the rungs and providing further stiffening and guiding support for the second section 39.

As will be noted from FIG. 3, the section 39 is formed similarly to the section 35, each of the rails 39a and 3% thereof having in addition an offset therein, said rails supporting rungs 43 in a substantially identical manner to the manner in which the rungs 41 are supported. Angles 39g and 39h are also fixed to the rails 39a and 39b respectively.

The third section 40 comprises the spaced side rails 45 which are identical and may be formed of fiberglass if desired to effect the necessary insulating function which may be desirable under some circumstances. Suitable rungs 45 are fastened to angles 45b and 45c which extend along the rails 45.

As illustrated in FIG. 4 and in a largely diagrammatic manner, the means for extending and retracting the ladder sections are shown as including an endless chain arrangement 46 mounted on sprockets 47 and 48 carried at opposite ends of the section 35. In the actual construction, the chain will be provided in duplicate to extend about centrally along the rungs 41 above and below the same intermediate the sides 35a and 35b.

Extending upwardly from the upper lap of the chain 46 as illustrated in FIG. 4, is a suitable arm 48 fastened to one of the rungs 43 of the second section 39, the side shown being designated 39a. This arm 48 is connected about centrally of one of the rungs 43 and in view of the construction it will be apparent that movement of the chain 46 in the direction of the arrow 50 for example, will cause the section 39 to move in the same direction. It will be apparent that movement of the chain 50 in the opposite direction will effect a retracting motion of the section 39.

Suitably reaved over sheaves designated 51 and 52 is a cable 53 connected at one end 54 with the first section 35 of the ladder assembly and at the end 55 to the other end of said section. The cable 53 will be provided as one of a pair and on each the upper laps thereof have mounted an upstanding arm 56 which is connected to one of the rungs 45a of the third or outer section 40 of the ladder assembly 33.

From this disclosure, it will be seen that as the chain 46 moves the part 48 connected to the rung 43 and thereby the section 39 outwardly, the cable 53 will be similarly actuated so that the arm 56 will project the section 40 in like manner.

The structure heretofore described in detail will provide for extension and retraction of the respective ladder sections 39 and 40 in a manner that will effect uniform outward displacement thereof, and retraction as required, and as operated by a suitable electric motor unit 57 indicated in FIG. I, mounted at the lower end of the ladder assembly and specifically the first section 35 thereof. This motor includes a reduction and is suitably mounted and connected so as to drive the chain 46 in a manner which will be obvious to those skilled in the art.

At the outer end of the third section 40 of the ladder assembly 33 there is provided a pair of offstanding arms 58, pivotally connected at 59 to a platform unit 60 which may be a basket carrying a platform 61 thereon.

A slave piston and cylinder unit 62 is connected at one end 63 to the arm 58 and at the other end at 64 to the platform unit 60 in such a manner that relative rotation of the platform unit 60 may be effected when the slave piston and cylinder unit 62 is operated by a master cylinder unit 66 mounted adjacent the pivot 34 of the ladder assembly 33.

The master cylinder unit 66 is connected to the vertically extensible and retractable member 11 at one end at 67 and at the other end 68 to the ladder section 35, there being suitable hose and pipe connections between the master and slave units so that extension or outward movement of the piston 69 of the unit 66 will similarly result in outward movement of the piston 62a of slave unit 62.

As indicated, the platform unit 60 is equipped with a control box at 70 which has connections therein as indicated in FIG. 5, with a base terminal block 71, the base terminal block 71 in turn connected with control box 72 mounted in the cab as shown in FIG. 1, for example.

Regulation of the various levers in the top unit in accordance with the directions set forth in FIG. 5, will in turn result in corresponding movements of the respective parts in a manner which is believed to be apparent. By suitable interconnection which is not shown in detail as it is not claimed as a part of this invention, the bottom control box is likewise arranged and according to directions carried thereon switches may be operated, resulting in corresponding movements of the respective parts likewise.

In FIG. 6, the hydraulic system is illustrated. The hydraulic piston and cylinder arrangement provided in the extensible and retractable member and specifically the portion 22 thereof, with suitable valves and pumps and reservoirs placed in a manner illustrated with check valves where required and including control valves in accordance with desired practice in hydraulic operation, none of the foregoing forming specifically a part of this invention, but disclosure being provided for clarity.

It is of course understood that the control boxes of the respective switches in which movement designations are indicated, will in turn result in the operation of the hydraulic pump 73 for example, to direct the pressure to the member 22, and in turn permit the pressure to be withdrawn from such member to permit lowering action to take place, the operation not being further described but obvious to those skilled in the art.

In view of the foregoing, it will be apparent that there has been disclosed a mechanism of novel form which permits the mounting of a single vertical member on a transport vehicle so that the member as indicated at 9 may extend above the cab or behind the cab or through a roof of a van to enable the control and manipulation of aerial lift apparatus as described or similar thereto, the advantages of the aerial lift platform at the end of the ladder being well-known, but as herein provided, unique, since the platform may be lowered into a position for ready access from the vehicle and raised as required with the additional flexibility made possible by the ladder assembly as contrasted with the usual boom arrangement of prior devices.

Iclaim:

1. In aerial lift apparatus including a transport vehicle, a drivers station on said vehicle, and a bed on said vehicle, the combination comprising: a boom unit mounted on said bed adjacent said drivers station including a base portion fixed to said bed, a cylindrical vertical column rigidly connected to and extending upwardly from said base, said column including a vertically extensible and retractable member therewithin, a ladder assembly pivotally connected intermediate its ends to the upper end of said retractable member, said ladder assembly including first, second and third telescoping sections, one of which includes a personnel platform at one end thereof, endless chain means carried by said first section including a connection extending upwardly therefrom to said second section, cable means connected at its ends to said first section and extending over sheaves in said second section, connecting means from said cable intermediate its ends to said third section, operating means carried by said ladder assembly to actuate said chain and cable between positions to extend and retract said sections, said cable means actuated in response to movement of said second section.

2. The combination as claimed in claim 1, wherein the extensible and retractable member is a part of a compound hydraulic piston and cylinder assembly.

3. The combination as claimed in claim 1, wherein the column is rigidly fixed to the base, the rotatable element is rotatably mounted in said column the lower end including gear means for rotating the element, the extensible and retractable member being mounted within said element, said member comprising an hydraulic piston and cylinder set, the upper end of said set having the pivotal connection with the ladder assembly as stated. 

1. In aerial lift apparatus including a transport vehicle, a driver''s station on said vehicle, and a bed on said vehicle, the combination comprising: a boom unit mounted on said bed adjacent said driver''s station including a base portion fixed to said bed, a cylindrical vertical column rigidly connected to and extending upwardly from said base, said column including a vertically extensible and retractable member therewithin, a ladder assembly pivotally connected intermediate its ends to the upper end of said retractable member, said ladder assembly including first, second and third telescoping sections, one of which includes a personnel platform at one end thereof, endless chain means carried by said first section including a connection extending upwardly therefrom to said second section, cable means connected at its ends to said first section and extending over sheaves in said second section, connecting means from said cable intermediate its ends to said third section, operating means carried by said ladder assembly to actuate said chain and cable between positions to extend and retract said sections, said cable means actuated in response to movement of said second section.
 2. The combination as claimed in claim 1, wherein the extensible and retractable member is a part of a compound hydraulic piston and cylinder assembly.
 3. The combination as claimed in claim 1, wherein the column is rigidly fixed to the base, the rotatable element is rotatably mounted in said column the lower end including gear means for rotating the element, the extensible and retractable member being mounted within said element, said member comprising an hydraulic piston and cylinder set, the upper end of said set having the pivotal connection with the ladder assembly as stated. 